Three Basic Organ in Plant Reproductive shoot (flower) • Three basic organs evolved: roots, stems, and leaves • They are organized into a root system and a shoot system Terminal bud Node Internode Terminal bud Shoot system Vegetative shoot Leaf Blade Petiole Axillary bud Stem Taproot Lateral roots Figure 35.2 Root system The Three Basic Plant Organs: Roots, Stems, and Leaves • The basic morphology of vascular plants – Reflects their evolutionary history as terrestrial organisms that draw nutrients from two very different environments: below-ground and above-ground Roots • A root – Is an organ that anchors the vascular plant – Absorbs minerals and water – Often stores organic nutrients AKAR / ROOTS • Fungsi Akar • Perkembangan Akar • Tipe – Tipe akar • Modifikasi Akar • Simbiosis di akar http://w3.dwm.ks.edu.tw/bio/activelearner/35/images/ch35summary.gif Fungsi Akar • Attachment to substrate (ground, etc) • Water and nutrien uptake • Transport In several plants: • Food storage • Oxygen uptake • Climber • In most plants – The absorption of water and minerals occurs near the root tips, where vast numbers of tiny root hairs increase the surface area of the root Figure 35.3 Perkembangan akar Primary Growth of Roots Cortex • The root tip is covered by a root cap, which protects the delicate apical meristem as the root pushes through soil during primary growth • The primary growth of roots – Produces the epidermis, ground tissue, and vascular tissue Epidermis Key Root hair Dermal Zone of maturation Ground Vascular Zone of elongation Apical meristem Root cap Figure 35.12 Vascular cylinder 100 m Zone of cell division • Lateral roots Arise from within the pericycle, the outermost cell layer in the vascular cylinder 100 m Emerging lateral root Cortex Vascular cylinder 1 2 Epidermis Lateral root Figure 35.14 3 4 Sistem Perakaran Tipe Akar Berdasarkan Pembentukannya • Akar Tunggang • Akar Serabut • Akar Adventif (lainnya) Tipe – Tipe Akar Akar papan/banir Akar tunjang • Many plants have modified roots (a) Prop roots Figure 35.4a–e (d) Buttress roots (b) Storage roots (c) “Strangling” aerial roots (e) Pneumatophores